Looms



2 Sheets-Sheet l LOOMS July Z6, 1955 J. R. wALToN mea June 28, 1952 July25, 1955 J. R. WALTON 2,713,876

INVENTOR.' jfs/4^ Wa-j/ Muro/V BY 7% yg.

United States Patent Gee 2 ,7 l 3 ,8 76 Patented July 26, 1 955 LOGE/ESJohn Ridgway Waiton, Bowereiy, Langeiire, Settle, England, assigner, bymestre assignments, to Chicopee Manufacturing Corp., New Brunswick, N.J., a corporation of Massachuetts Application lune Z8, 1952, Serial No.296,113

Claims priority, application Great Britain August 31, 1951 6 Claims.(Cl. 139-434) This invention relates to looms and more particularly toimproved means for producing the shuttle motion, known as the pickingmechanism.

It is well known that the majority of the noise in a normal loom is dueto the impact between the picker and the shuttle and due t anotherimpact between the shuttle f and the swells which bring the shuttle torest at each end of the slay or shuttle race-board. The need for theseviolent impacts is due to the need to accelerate the shuttle to avelocity high enough to carry it with certainty through the shed, and todestroy this high velocity when the pick or shuttle travel from one endof the slay to the other, is completed. Moreover the shuttle must beaccelerated to and decelerated from this high velocity over a shortdistance, and consequently the numerical value of shuttle accelerationis Very high indeed.

In order to overcome these disadvantages it is necessary to reduce thenumerical value of shuttle acceleration and deceleration by the maximumpossible amount.

In practice this means that the shuttle must continue to accelerateuntil it reaches a point midway through the shed, and having reachedthat point it must then decelerate for the remainder of its travel,which condition in turn imposes the need for the shuttle to be undercontrol at all times during its travel to and fro across the slay, evenwhen it is between the two layers of warp threads known as the shed.

It has been proposed to produce a shuttle motion having these conditionsby magnetically controlling the shuttle in accordance with amechanically oscillated traveller, the shuttle being mounted on wheelsrunning on the f,

slay of the loom. The rate of work of a loom with a magneticallycontrolled wheeled shuttle is, however, limited by practicalconsiderations. The total magnetic tlux linking the shuttle with themechanical oscillatory traveller must be large and this means the use ofheavy and cumbersome magnets in the traveller and in the shuttle.Limitations are thus imposed on the amount of shuttle accelerating forceavailable on the value of maximum shuttle acceleration and on the meanshuttle velocity. Because of the weight of the magnets in the shuttleand the force of the magnetic linkage, the resistance of the wheels onthe slay is high and results in mechanical losses and damage to the warpthreads.

It is the object of the present invention to provide a loom having animproved means of shuttle motion which will reduce the noise ofoperation to a minimum, will permit the use of relatively lightshuttles, will permit the shuttle to be always under a driving inuenceduring its travel across the slay, will permit the manufacture of widefabrics, and will obviate the disadvantages experienced in thepreviously proposed magnetically propelled shuttles.

In the broadest aspect of the invention a loom having a shuttle adaptedto be moved by, and under continuous control of a travellerreciprocating underneath the warp threads, is characterised by thetraveller being formed so as to provide a recessed seating for snuglyreceiving with Warp threadsA interposed, a supporting part of theshuttle.

. According to the invention in a narrower aspect, a loom having ashuttle adapted to be moved by, and under the control of, a travellerreciprocating underneath the warp threads, is characterised by thetraveller having at least one pair of wheels forming between them arecessed seating for snugly receiving with warp threads interposed, awheel supporting the shuttle.

In the above statement, and hereinafter in the specification and claims,the term wheel is not intended to exclude a roller, and also in thefollowing description the term roller is not intended to exclude awheel.

Preferably the pair of wheels project up above the slay, so that thewarp threads are humped, to an extent controlled by auxiliary wheelsadapted to run along the underside of the slay. The auxiliary wheels arepreferably urged against the underside of the slay by an underneath pairof wheels running upon a supporting surface and resiliently pulledtowards each other.

The slay is preferably a hollow structure having an upper part providinga gap through which the travellers pair of wheels project and providingunder surfaces on each side of the gap for the auxiliary wheels to runalong. The bottom part of the structure may provide the sup portingsurface for the said underneath pair or wheels.

Guiding means may be located above the shuttle, at least over the endportions of the shuttle travel, so as positively to constrain theshuttle supporting part to nest in the recessed seating provided by thetraveller. The traveller and the shuttle may comprise magneticallyattracting means urging the shuttle supporting part to nest in therecessed seating provided by the traveller.

The traveller is preferably reciprocated with a simple harmonic motion,which may be produced by means of a Scotch yoke rotating a wheel aboutwhich is entrained a belt whose ends are connected to the traveller.

The invention is illustrated by way of example in the accompanyingdrawings, in which:

Figure 1 is a front elevation on an enlarged scale of a mechanism forproducing the simple harmonic reciprocating motion of the traveller.

Figure 2 is a front elevation of part of a loom showing the slay andmeans for reciprocating the traveller.

Figure 3 is an end elevation of Figure l.

Figure 4 is a front sectional elevation of the shuttle and travellershown in position on the slay ot' loom.

Figure 5 is an end sectional elevation of Figure 4.

Referring to Figure l, a shaft 1 is caused to rotate with constantangular velocity by suitable means (not shown) secured to the shaft 1 isa disc 2 which carries rigidly attached, a pin 3. A block member 4 isrotatably mounted on the pin 3 and is adapted to slide in a slot 5formed in a cross head 6. The cross head 6 is formed integrally withrods 7 and S projecting respectively from either side thereof, whichrods are supported in bearings 9 so that they are free to move lonly inan axial direction. It will be seen that rotation of the shaft 1 willcause the rods 7 and 8 to reciprocate axially according to a simpleharmonic law. The mechanism just described is widely known by the nameScotch yoke.

The rod 8 has a thickened portion in which rack teeth 11 are formed andengage with similar teeth 18 formed on a pinion 13, which is rigidlysecured on the axle 14 of a wheel 15 of larger diameter, the axle beingsupported in suitable bearings (not shown). It will be seen that bymeans of the Scotch yoke mechanism described above the wheel 1S willrotate alternatively to the right and to the left through the rack l1and pinion 13 and that its reversal will obey a simple harmonic law.

Referring to Figures l, 2 and 3 a ilexible wire or band 16 is passedaround the wheel 15'several times, the wire being secured to the wheelby suitable means (not shown) in order to prevent slip, and then passesaround four idler wheels 17 identically formed which are situated two ateach end of a hollow square sectioned loom slay 18 forming a shuttlerace-board 19. The wire or band passes along the inside of the hollowslay 18 and is secured to a traveller generally indicated at 20 which ismounted within the slay so that it is free to reciprocate in a planeparallel to the slay 1S and race-board 10. It will be seen that thetraveller 20 will reciprocate according to a simple harmonic law, andthat the amplitude of its oscillations may conveniently be adjusted byselecting a suitable radial distance between the shaft 1 and the pin 3and a suitable ratio of diameter of the wheel 15 to the pinion 13.

The hollow slay 18 is supported in conventional manner by slay swords26, Figures 2 and 3, which pivot about a point Z at the intersection oftwo centre lines A and B. The point P on the periphery of the wheel 15and the Wire or band 16 extending therefrom are arranged to be in linewith the pivotal point Z so that the slay may pivot without altering theeifective length of the wire or band 16 although the wheel 15 remains ina fixed plane. The object of the pivoting of the slay is to allow thereed shown at 26a to beat up the weft threads (not shown) in the usualway during weaving. Apart from the modications just described thegeneral construction and layout of the slay is in accordance with normalpractice.

Referring now to Figures 4 and 5 the traveller generally indicated at2t) consists of two longitudinal plates 21 spaced apart from each otherso as to receive between them four wheels 22 positioned two at each endof the plates 21. The wheels are mounted to transverse axles 23 (oneonly of which is shown in Figure 5) the ends of which are secured in theplates 21 and assist in maintaining the two plates in their spacedrelationship. Auxiliary wheels 24 are mounted on stub-axles 25 securedto the outside of each plate 21 co-axially with each of the wheels 22.The auxiliary wheels are free to rotate independently of the wheels 22.

The slay 18, as previously stated, is a hollow structure of squaresection in which the traveller 20 is mounted for reciprocation, and theupper surface or raceboard 19, of the slay has a longitudinal gap 27(Figures 3 and 5) therein extending throughout the length of the slay,through which the wheels 22 of the traveller mounted in the slay areadapted to project. wheels 22 through the gap is controlled by theauxiliary wheels 24 which are adapted to run along the underside of theraceboard 19 as clearly shown in Figure 5. The auxiliary wheels 24 areurged upwardly against the underside of the raceboard 19 by two pairs ofrollers 28 which are positioned one pair underneath each pair oftraveller wheels 22. Each pair of rollers 28 is adapted to run along thebottom inner surface or door 29 of the slay 18, and the two wheels ofeach pair are resiliently and continuously pulled towards each other bymeans of two coiled tension springs 30 which have their ends secured tothe projecting ends of two axles 31 on which the rollers 28 are mountedas clearly shown in Figure 4. It will be seen that the pull of thesprings 30 will cause each pair of rollers 28 to act as wedges betweenthe inner surface 29 of the slay bottom and the traveller wheels 22 thuspressing the auxiliary wheels 24 continuously against the underside ofthe raceboard 19.

Means 32 are provided for attaching the ends of the wire or band 16 tothe traveller at each end thereof.

A shuttle 33, adapted to be moved by and under the control of, thetraveller 20, is provided with two rollers 34 each mounted within theshuttle body on an axle 35. Each of the rollers is shown as having adiameter equal to that of the travellers wheels 22, but it will beappreciated that this is not a necessity and the ratio of the diametersof the rollers 34 and wheels 22 may be so selected as to make for aconvenient ratio between the horizontal and vertical components of theaccelerating force. The rollers 34 are so positioned in the shuttle bodythat when the shuttle The extent of projection of the tif) is placedupon the raceboard 19 immediately over the traveller 20, each rollerwill enter respectively the recessed seating formed between one of thepairs of travellers wheels 22 mounted at each end of the traveller andfit snugly therein.

It will be seen from Figure 4 that a part of the shuttle body at eachend is cut away on its underside so as to accommodate the portions ofthe wheels 22 projecting above the raceboard 19, and also so that agreater portion of each roller 34 projects from the shuttle body.

The shuttle is provided with a pair of soft iron armatures 36 positionedin the lower part of its body which are adapted to co-operate with apair of horseshoe magnets 37 carried by the traveller 20 so as tocomplete a magnetic circuit. A small air gap 38 is left between thearmatures and magnets to allow the free passage between them of warnthreads indicated by a dotted line 39 in Figure 4.

The shuttle is equipped with the usual arrangements for carrying the copor package of weft together with the usual means for guiding the threadout of the shuttle, but these are not shown so as to avoid confusion inthe drawings.

The operation of the mechanism will now be described. Let it be supposedthat the traveller is moved to the right in Figure 4 of the drawings,under the influence of the wire or band 16 functioning as previouslydescribed. The rollers 28 will be rotated in a clockwise direction byvirtue of their frictional adhesion with the inner surface 29 of thebottom of the slay. This rotational movement will cause the travellerswheels 22 to rotate in an anti-clockwise direction by virtue of theirfractional adhesion with the rollers 28. This in turn will cause theshuttle rollers 34 to rotate in a clockwise direction due to theirfrictional adhesion with the travellers wheels 22, and the shuttle willmove to the right keeping its position above the traveller. The weightor mass of the shuttle imposes a denite frictional grip between theshuttle rollers and the travellers wheels and this frictional grip ismagnified by the magnetic attraction of the armatures 36 and magnets 37.

The line of warp threads indicated by the dotted line 39 pass betweenthe shuttle rollers 34 and travellers wheels 22. Because of the factthat at any instant a point at the top of each travellers wheel 22 isstationary with respect to the warp threads under which each wheel isimmediately passing, the warp threads pass between the rollers 34 andwheels 22 without being disturbed in a lateral direction. In a verticaldirection, however, they are lifted a small amount equal to the extentto which the travellers wheels 22 project above the clay. It may bementioned that the points of contact of the shuttle rollers 34 with thetravellers wheels 22 are not completely stationary with respect to thewarp threads, there being a very slight horizontal component ofvelocity. This component, however, is not sufficient in practice toetect the warp threads in a lateral direction by any measurable amount.

When the traveller and the shuttle reach the limit of their travel tothe right in Figure 4, their movement is immediately reversed and thewheels 22, auxiliary wheels 24, rollers 28 and 34 will rotate in theopposite directions to those described as the traveller and shuttle moveto the left across the slay.

As the traveller and shuttle oscillate across the slay together inaccordance with a simple harmonic law, their acceleration will be at amaximum when they are at the limit of their travel at one or the otherend of the slay 18, the magnitude of this acceleration being dependentupon the square of the number of oscillations per unit of time. At thispoint in their movement there is a tendency for the shuttle to continueits movement away from the center of the slay and to resist the force ofthe magnetic attraction of the armatures 36 and magnets 37 to reverseits direction of travel and accelerate it back towards the center of theslay.

If the value or magnitude of the force accelerating the shuttle exceedsthe force available to hold the shuttle to the traveller, the shuttlewill obviously leave its position over the traveller and it will ceaseto follow the movements ofthe traveller. However, in order for this tohappen the shuttle must rise a little to clear the projecting portionsof the travellers` wheels 22 and this action must increase the air gap38 between the armatures 36 and magnets 37. The magnetic attractionbetween the armatures 36 and magnets will resist the tendency of theshuttle to rise from its position on the traveller, and will impart tothe shuttle a horizontal acceleration force. The magnetic ilux isstressed in tension instead of in shear as has previously been proposed,and this stressing in tension has been found in practice to be far moreeffective than the usual way of stressing the magnetic flux in shear.

In order to assist the magnetic attraction of the armatures 36 andmagnets 37 to hold the shuttle on to the traveller at the points ofreversal of their direction of travel, there may be arranged guidingmeans located over the end portions of the slay to positively constrainthe shuttle to maintain its position on the traveller with its rollers34 nesting in the recessed seatings formed by the travellers wheels 22.Such a guiding means is shown in Figure 4 and takes the form of a numberof rollers or wheels 40 rotatedly mounted in a frame 41 secured bysuitable means (not shown) over the slay at a height suicient for therollers or wheels to be effective in their constraining action, withoutretarding the travel of the shuttle.

The armatures 36 and magnets 37 are not absolutely essential, but if notcarried by the shuttle and traveller respectively, it would be necessaryto have a top guide such as described located above the full length, ormost of the length of the slay.

In practice the traveller'sl wheels 22 may be made to project an amountsucicient for the shuttle rollers 34 to rest lightly on the raceboard 19on either side of the gap 2.7.

Since the rate of shuttle travel is relatively slow, it is necessarythat the normal beat-up of the slay shall be modied to allow the shuttlesuiiicient time to move through the shed. This may be achieved either bymeans of cams with suitable dwells, or by means of a crank andconnecting rod such as is commonly used in looms, but with theconnecting rod only slightly longer than the radius of the crank so asto produce the desired period of dwell.

It will be appreciated that with the improved construction of shuttlemotion according to the invention, if armatures and magnets are used,only very light magnets need be provided. Another advantage is that asthe shuttle is firmly held onto the traveller, there is no relativevibration between the two.

ln addition to being practically noiseless, a loom having the improvedshuttle motion is capable of weaving fabrics of unlimited width, andsince the shuttle does not dwell at the limit of its travel across theslay, a very high rate of working may be achieved in spite of the lowvalue of maximum velocity of the shuttle.

What is claimed is:

l. In a loom the improvement comprising, a slay comprising a raceboardpositioned below and extending across the warp threads and a floorspaced below said raceboard, said raceboard having a longitudinal gapextending the width of the warp threads, a traveler mounted in the slayfor reciprocating movement from one side of the warp threads to theother, said traveler having a front and a rear pair of wheels projectingthrough the gap of the race-y board, the wheels in said pairs beingslightly spaced from one another with their axes extending transverselyof the slay in substantially the same horizontal plane, a front and arear pair of rollers arranged to roll longitudinally along the tloor ofthe slay, the rollers of each of said pairs being spring urged togetherand supporting a corresp'onctingv pair of said spaced wheels' betweenthem, auxiliary wheels axially fixed on said traveler urged against theunderside of said raceboard by the springs of said pairs of rollersacting through the spaced wheels of said traveler, and a shuttle abovethe warp threads mounted on a front anda rear roller, each of saidshuttle rollers being supported by and nesting with a corresponding pairof spaced wheels of said traveler, whereby the traveler supports theshuttle with warp threads interposed and the shuttle moves with thetraveler in a reciprocating manner.

2. The improvement in a loom according to claim l, wherein the travelerand the shuttle contain magnetically attracting means.

3. In a loom the improvement comprising, traveler guide means spacedbelow and extending across the warp threads, a traveler mounted onrollers in contact with said guide means for reciprocating movement fromone side of the warp threads to the other, said traveler comprising apair of wheels exposed to the warp threads and slightly spaced from oneanother with their axes transverse to the slay, said rollers comprisinga pair of rollers spring urged together and adapted to support said pairof wheels between them, the tendency of said pair of rollers being tocome together and lift said pair of wheels into the warp threads, meansfor preventing said pair of wheels from rising above a set level withrespect to the warp threads, and a shuttle above the warp threadsmounted on rolling means, said rolling means comprising a rollersupported by and nesting with the pair of spaced wheels of saidtraveler, whereby the traveler supports the shuttle with warp threadsinterposed and the shuttle moves with the traveler in a reciprocatingmanner.

4. The improvement in a loom according to claim 3, wherein the travelerand the shuttle contain magnetically attracting means.

5. In a loom the improvement comprising, a slay cornprising a race boardpositioned below and extending across the warp threads and a iloorextending below said race board, said race board having a longitudinalgap extending the width of the warp threads, a traveller in the slaymounted on a pair of rollers in contact with said iloor forreciprocating movement from one side of the warp threads to the other,said traveler having a pair of spaced wheels projecting through the gapof the race board and auxiliary rolling means in contact with theunderside of the race board, said pair of wheels being supported betweensaid pair of rollers and said rollers being spring urged togetherwhereby said pair of wheels is urged upward as the rollers tend to cometogether and said auxiliary rolling means constrain said pair of wheelsfrom further upward movement, and a shuttle above the warp threadsmounted on rolling means, said shuttle rolling means being supported byand nesting with the spaced wheels of said traveler, whereby thetraveller supports the shuttle with warp threads interposed and theshuttle moves with the traveller in a reciprocating manner.

6. In a loom the improvement comprising, traveller guide means spacedbelow and extending across the warp threads, a traveller mounted onrollers in contact with said guide means for reciprocating movement fromone side of the warp threads to the other, said traveller comprising apair of wheels exposed to the warp threads and slightly spaced from oneanother with their axes transverse to the slay, said rollers comprisinga pair of rollers resiliently urged together and adapted to support saidpair of wheels between them, the tendency of said pair of rollers beingto come together and lift said pair of wheels into the warp threads,means for preventing said pair of wheels from rising above a set levelwith respect to the warp threads, and a shuttle above the warp threadsmounted on rolling means, said rolling means comprising a rollersupported by and nesting with the pair of spaced wheels References Citedin the file of this patent UNITED STATES PATENTS 99,586 Norfolk Feb. 8,1870 133,868 Lyall Dec. 10, 1872 234,521 Bigsby Nov. 16, 1880 8 LoyndOct. 9, 1900 Bond Dec. 26, 1905 Chernack Apr. 10, 1917 Rourke Oct. 9,1934 Cooper May 2, 1950 FOREIGN PATENTS Great Britain July 29, 1899

